Electrical devices and equipment in buildings or vehicles are usually supplied via an electrical network over which the electrical power is distributed. The latter is here provided by one or more power supply units and transmitted over electrical lines. Due to the combined use of electrical lines within such a network, electrical spurious signals released by individual devices via their connection to the electrical network can be detected by other devices.
Electrical consumers in vehicles and in particular in aircraft must satisfy strict electrical requirements, and can only release slight electrical disturbances in an electrical network and electromagnetic disturbances in their environment. The interpretation of an electrical spurious signal detected by an automatic fault detector integrated into a device is hampered by the necessary recognition of whether the electrical spurious signal comes from inside or outside the respective device. As a consequence, it is rather difficult to unequivocally diagnose and identify a detected error within the electrical system.